Took the boat ride to Japhet's folly and killed everyone in sight except Andelaisa Vendichi. The quest arrow say's I'm supposed to "report" to her, but she's totally zoned out. Can't get a response, even giving her a good smack or chucking her in the sea with Unrelenting Force doesn't wake her up (in the latter case she just climbs out and returns to where she was waiting).

OK, so I accidentally hit her when I attacked the bandit she was fighting. Must be brain damage.

Meanwhile the game won't let me off the island. I try and swim, but I seem to be unable to move past the edge of tile. If I try to return to the boat we came in on my alleged allies attack me, and anyway they won't let a ladder down.

It's starting to look like I'll have to undo about 2 hours of play.

Now I found a report of a very similar problem for the 360, but the report says that attacking her will bring her out of it. On the PS3 it doesn't.

One possible symptom, when I'm anywhere near hear the game shows her damage bar in the enemy position. You don't generally see that with non-hostiles.